Embed sound in flex with variable String

I'm looking to do something like:

private static const fooDir : String = "foo";
[Embed(source = foo + "/foobar.mp3")]
private开发者_如何学Python var Foo:Class;

Flex is only accepting the string if it's written fully out as [Embed(source = "foo/foobar.mp3")]. Is there a way around this?

Unfortunately you can't place variables in Embed meta data (Flex 4). Possibly in future versions.